1. Field of the Invention
This invention relates generally to a hydrocarbon conversion catalyst and method and more particularly concerns a catalyst and method for recovering upgraded liquid products from solid carbonaceous materials.
2. Description of the Prior Art
It is generally desirable in catalytic processes for upgrading hydrocarbon streams to provide a catalyst having a high level of small- or intermediate-sized pores because, for a given total pore volume, distribution thereof in many smaller pores gives a relatively higher surface area than distribution thereof in a smaller number of relatively larger pores. However, small pores are more susceptible to plugging than are larger pores, and thus if insufficient large pores are present, catalyst activity often declines substantially during use. If catalyst activity declines too rapidly, excessive losses in efficiency and/or increases in catalyst replacement costs are incurred. Thus, sufficient large and small pores must be present.
For example, Kim et al., U.S. Pat. Nos. 4,257,922 and 4,294,685, disclose a catalyst comprising a molybdenum component, alone or promoted by a cobalt component and/or a nickel component, on support particles having a bimodal pore distribution, with a peak concentration of small pores having diameters below about 600 .ANG. and a peak concentration of larger pores having diameters above about 600 .ANG., the average diameter of the smaller pores being in the range of 100-200 .ANG., and the average diameter of the larger pores being in excess of 1,000 .ANG., and the catalyst having at least 5% of the total pore volume, as determined by mercury penetration and nitrogen desorption measurements, in the larger pores and at least 70% of the total pore volume in the smaller pores. This catalyst is disclosed as being suitable for the hydroconversion of coal solids to liquid and gaseous products.
Hensley et al., U.S. Pat. No. 4,225,421, disclose a similar bimodal catalyst consisting essentially of at least one active hydrogenation metal selected from Group VIB deposited on a support comprising alumina wherein the catalyst has a surface area within the range of from about 140 to about 300 m.sup.2 /gm, a total pore volume based upon measurement by mercury penetration within the range of from about 0.4 cc/gm to about 1.0 cc/gm, and comprising about 60% to about 95% of its micropore volume in micropores having diameters within the range of from about 50 .ANG. to about 200 .ANG., 0% to about 15% of its micropore volume in pores having diameters within the range of about 200 .ANG. to about 600 .ANG. and about 3% to about 30% of the total pore volume in macropores having diameters of at least 600 .ANG.. The catalyst is disclosed for use in a process for hydrodemetallation and hydrodesulfurization of hydrocarbon feedstocks containing asphaltenes and metals, such as crude oils, topped crude oils, and petroleum hydrocarbon resids, both atmospheric and vacuum resids, oils obtained from tar sands, and resids derived from tar sands oil.
The aforesaid patents disclose a molybdenum component as a suitable catalytically active substance and state that other known catalysts such as nickel and/or cobalt can be employed as promoters for the molybdenum. However, such patents contain no suggestion to add a chromium component to the metal components on the bimodal supports disclosed therein.
It has been found that the addition of a chromium component to catalysts comprising a Group VIB metal alone or promoted by a Group VIII metal component and deposited on supports having different physical characteristics than those described hereinabove gives highly desirable results in a wide range of applications. For example, Quick et al., U.S. Pat. No. 4,181,602 disclose a process for hydrotreating a heavy hydrocarbon stream containing metals, asphaltenes, nitrogen compounds, and sulfur compounds, which process comprises contacting the stream under suitable conditions and in the presence of hydrogen with a catalyst comprising a hydrogenating component selected from the group consisting of (1) molybdenum, chromium and a small amount of cobalt, (2) their oxides, (3) their sulfides, and (4) mixtures thereof on a large-pore, catalytically active alumina, and having a pore volume, as determined by nitrogen desorption, within the range of about 0.4 cc/gm to about 0.8 cc/gm, a surface area within the range of about 150 m.sup.2 /gm to about 300 m.sup.2 /gm, and an average pore diameter within the range of about 100 .ANG. to about 200 .ANG.. The catalyst that is employed in the process disclosed in U.S. Pat. No. 4,181,602 has about 0% to about 10% of its pore volume in pores having diameters that are smaller than 50 .ANG., about 30% to about 80% of its pore volume in pores having diameters of about 50 .ANG. to about 100 .ANG., about 10% to about 50% of its pore volume in pores having diameters of about 100 .ANG. to about 150 .ANG., and about 0% to about 10% of its pore volume in pores having diameters that are larger than 150 .ANG.. Typical feedstocks that can be treated by the process disclosed in U.S. Pat. No. 4,181,602 include crude oils, topped crude oils, petroleum hydrocarbon residua, both atmospheric and vacuum residua, oils obtained from tar sands and residua derived from tar sand oil, and hydrocarbon streams derived from coal.
Quick et al., U.S. Pat. No. 4,188,284 disclose a process for hydrotreating a heavy hydrocarbon stream containing metals, asphaltenes, nitrogen compounds, and sulfur compounds, which process comprises contacting the stream under suitable conditions and in the presence of hydrogen with a catalyst comprising a hydrogenating component consisting essentially of a member selected from the group consisting of (1) molybdenum and chromium, (2) their oxides, (3) their sulfides, and (4) mixtures thereof on a large-pore, catalytically active alumina and having a pore volume, as determined by nitrogen desorption, within the range of about 0.4 cc/gm to about 0.8 cc/gm, a surface area within the range of about 150 m.sup.2 /gm to about 300 m.sup.2 /gm, and an average pore diameter within the range of about 100 .ANG. to about 200 .ANG.. The catalyst that is employed in the process disclosed in U.S. Pat. No. 4,188,284 has about 0% to about 10% of its pore volume in pores having diameters that are smaller than 50 .ANG., about 30% to about 80% of its pore volume in pores having diameters within the range of about 50 .ANG. to about 100 .ANG., about 10% to about 50% of its pore volume in pores having diameters within the range of about 100 .ANG. to about 150 .ANG., and about 0% to about 10% of its pore volume in pores having diameters that are larger than 150 .ANG.. The process disclosed in U.S. Pat. No. 4,188,284 is stated to be useful for hydrotreating heavy hydrocarbon streams such as petroleum residua, both atmospheric resids and vacuum resids, tar sands oils, tar sands resids, and liquids obtained from coal. In addition, the process may be employed to satisfactorily hydrotreat petroleum hydrocarbon distillates, such as gas oils, cycle stocks, and furnace oils.
Quick et al., U.S. Pat. No. 4,191,635 disclose a process for cracking a heavy hydrocarbon stream containing metals, asphaltenes, nitrogen compounds, and sulfur compounds, which process comprises: (a) contacting the stream in a hydrotreating zone under hydrotreating conditions and in the presence of hydrogen with a hydrotreating catalyst comprising a hydrogenating component comprising at least the hydrogenating metals molybdenum and chromium, such hydrogenating metals being present in the elemental form, as oxides, as sulfides, or mixtures thereof, deposed on a large-pore, catalytically active alumina to reduce the metals content in the stream, to convert the asphaltenes, nitrogen compounds, and sulphur compounds in the stream, and to provide a hydrotreated product stream, said hydrotreating catalyst possessing a pore volume within the range of about 0.4 cc/gm to about 0.8 cc/gm, as determined by nitrogen desorption, a surface area within the range of about 150 m.sup.2 /gm to about 300 m.sup.2 /gm, and an average pore diameter within the range of about 100 .ANG. (10 nm) to about 200 .ANG. (20 nm); and (b) catalytically cracking at least a portion of said hydrotreated product stream in a catalytic cracking zone under catalytic cracking conditions and in the presence of a cracking catalyst to produce gasoline and distillates in improved yields.
The hydrotreating catalyst that is employed in the process disclosed in U.S. Pat. No. 4,191,635 can have about 0% to about 10% of its pore volume in pores having diameters that are smaller than 50 .ANG., about 30% to about 80% of its pore volume in pores having diameters of about 50 .ANG. to about 100 .ANG., about 10% to about 50% of its pore volume in pores having diameters of about 100 .ANG. to about 150 .ANG., and about 0% to about 10% of its pore volume in pores having diameters that are larger than 150 .ANG.. The hydrogenating component of the hydrotreating catalyst can comprise further a small amount of the hydrogenating metal cobalt. The process disclosed in U.S. Pat. No. 4,191,635 comprises further contacting the heavy hydrocarbon stream in a demetallization zone under demetallization conditions and in the presence of hydrogen with a demetallization catalyst prior to contacting said stream in the hydrotreating zone with the hydrotreating catalyst. Typical feedstocks that can be treated satisfactorily by the process disclosed in U.S. Pat. No. 4,191,635 include crude oils, topped crude oils, petroleum hydrocarbon residua, both atmospheric and vacuum residua, oils obtained from tar sands and residua derived from tar sand oil, and hydrocarbon streams derived from coal.
Hensley et al., U.S. Pat. Nos. 4,224,144, 4,278,566 and 4,306,965 disclose a process comprising contacting a hydrocarbon stream such as a petroleum distillate or similar material with hydrogen and a catalyst comprising chromium, molybdenum, and at least one Group VIII metal hydrogenation component deposited on a porous refractory inorganic oxide support, which process is effective in the removal of both sulfur and nitrogen from such a hydrocarbon stream in contrast to a catalyst which does not contain chromium with Group VIII metal.
The finished catalyst that is disclosed in U.S. Pat. Nos. 4,224,144, 4,278,566 and 4,306,965 should have a pore volume within the range of about 0.4 cc/gm to about 0.8 cc/gm, as determined by nitrogen desorption, a surface area within the range of about 150 m.sup.2 /gm to about 300 m.sup.2 /gm, and an average pore diameter within the range of about 60 .ANG. to about 200 .ANG.. The catalyst disclosed broadly in U.S. Pat. Nos. 4,224,144 and 4,306,965 should have about 0% to about 50% of its pore volume in pores having diameters that are smaller than 50 .ANG., about 30% to about 80% of its pore volume in pores having diameters of about 50 .ANG. to about 100 .ANG., about 0% to about 50% of its pore volume in pores having diameters of about 100 .ANG. to about 150 .ANG., and about 0% to about 20% of its pore volume in pores that are larger than 150 .ANG.. The catalyst disclosed in U.S. Pat. No. 4,278,566 and a preferred embodiment of the catalyst disclosed in U.S. Pat. Nos. 4,224,144 and 4,306,965 should have from 20 to 50% of its pore volume in pores having diameters that are smaller than 50 .ANG., about 30 to about 70% of its pore volume in pores having diameters of 50-100 .ANG., 0-20% of its pore volume in pores with diameters of 100-150 .ANG. and 0-10% of its pore volume in pores with diameters greater than 150 .ANG..
Typical feedstocks that can be treated satisfactorily by the process disclosed in U.S. Pat. Nos. 4,224,144, 4,278,566 and 4,306,965 generally comprise distillates from petroleum and tar sands as well as similar materials such as shale oil and fractions thereof. In addition to removing sulfur and nitrogen, treatment of gas oil and similar heavy distillate streams at high temperature in the process of this invention can achieve substantial hydrocracking of heavy components in such feedstocks.